System and method for additive manufacturing of an object

ABSTRACT

A method of additive manufacturing of a three-dimensional object is disclosed. The method comprises sequentially forming a plurality of layers each patterned according to the shape of a cross section of the object. In some embodiments, the formation of at least one of the layers comprises performing a raster scan to dispense at least a first building material composition, and a vector scan to dispense at least a second building material composition. The vector scan is optionally along a path selected to form at least one structure selected from the group consisting of (i) an elongated structure, (ii) a boundary structure at least partially surrounding an area filled with the first building material, and (iii) an inter-layer connecting structure.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/494,577 filed on Apr. 24, 2017, which is a continuation of U.S.patent application Ser. No. 14/112,252 filed on Oct. 17, 2013, now U.S.Pat. No. 9,649,811, which is a National Phase of PCT Patent ApplicationNo. PCT/IL2012/050137 having International Filing Date of Apr. 17, 2012,which claims the benefit of priority of U.S. Provisional PatentApplication No. 61/476,275 filed on Apr. 17, 2011. The contents of theabove applications are hereby incorporated by reference as if fully setforth herein.

FIELD AND BACKGROUND OF THE INVENTION

The present invention, in some embodiments thereof, relates to AdditiveManufacturing (AM) of an object, more particularly, but not exclusively,to a system and method for additive manufacturing of an object using acombination of materials and/or scanning patterns.

Additive manufacturing is generally a process in which athree-dimensional (3D) object is manufactured utilizing a computer modelof the object. Such a process is used in various fields, such as designrelated fields for purposes of visualization, demonstration andmechanical prototyping, as well as for rapid manufacturing (RM).

The basic operation of any AM system consists of slicing athree-dimensional computer model into thin cross sections, translatingthe result into two-dimensional position data and feeding the data tocontrol equipment which manufacture, in a layerwise manner, athree-dimensional structure on a working surface.

Additive manufacturing entails many different approaches to the methodof fabrication, including three-dimensional printing, laminated objectmanufacturing, fused deposition modeling and others.

In three-dimensional printing processes, for example, a buildingmaterial is dispensed from a dispensing head having a set of nozzles todeposit layers on a supporting structure. Depending on the buildingmaterial, the layers may then be cured or solidified using a suitabledevice. The building material may include modeling material, which formsthe object, and support material, which supports the object as it isbeing built. Various three-dimensional printing techniques exist and aredisclosed in, e.g., U.S. Pat. Nos. 6,259,962, 6,569,373, 6,658,314,6,850,334, 7,183,335 7,209,797, 7,225,045, 7,300,619, 7,479,510,7,500,846, 7,658,976 and 7,962,237, and U.S. Published Application No.20100191360, all of the same Assignee, the contents of which are herebyincorporated by reference.

AM facilitates rapid fabrication of functioning prototypes with minimalinvestment in tooling and labor. Such rapid prototyping shortens theproduct development cycle and improves the design process by providingrapid and effective feedback to the designer. AM can also be used forrapid fabrication of non-functional parts, e.g., for the purpose ofassessing various aspects of a design such as aesthetics, fit, assemblyand the like. Additionally, AM techniques have been proven to be usefulin the fields of medicine, where expected outcomes are modeled prior toperforming procedures. It is recognized that many other areas canbenefit from rapid prototyping technology, including, withoutlimitation, the fields of architecture, dentistry and plastic surgerywhere the visualization of a particular design and/or function isuseful.

The deposition of materials according to two-dimensional position datato form a layer can generally be accomplished by establishing a relativelateral motion between the dispensing device (e.g., printing head,extrusion nozzle, etc.) and the working surface along some motionpattern. Known in the art are two types of motion patterns, referred toas “raster scan” and “vector scan.” Raster scan is characterized by aback and forward relative motion between the dispensing device andworking surface, typically using several nozzles for paralleldeposition. During the raster scan all the locations on the workingsurface are visited by the dispensing device, wherein a controllerselectively activates and deactivates the dispensing nozzles for eachvisited location according to the two-dimensional position data. Invector scan, the dispensing device does not visit all the locations onthe working surface. Instead, the relative motion is along a pathselected based on the locations at which material deposition isrequired.

U.S. Pat. No. 6,193,923 to Leyden discloses a rapid prototypingtechnique in which a print head is displaced over a working surface inboth a scanning direction and an index direction. Leyden teaches twoscanning protocols. In one protocol a motion of the printing head in themain scanning direction is followed by a smaller increment of movementin a secondary scanning direction while no dispensing occurs, which inturn is followed by a reverse scan in the main scanning direction inwhich dispensing again occurs. In another protocol, the small secondaryscanning movements are performed while main scanning occurs. Leyden alsodiscloses vector scanning and a combination of vector scanning andraster scanning.

Several AM techniques allow additive formation of objects using morethan one modeling material. For example, U.S. Published Application No.20100191360 of the present Assignee, the contents of which are herebyincorporated by reference, discloses a system which comprises anadditive manufacturing apparatus having a plurality of dispensing heads,a building material supply apparatus configured to supply a plurality ofbuilding materials to the fabrication apparatus, and a control unitconfigured for controlling the fabrication and supply apparatus. Thesystem has several operation modes. In one mode, all dispensing headsoperate during a single building scan cycle of the fabricationapparatus. In another mode, one or more of the dispensing heads is notoperative during a single building scan cycle or part thereof.

SUMMARY OF THE INVENTION

According to an aspect of some embodiments of the present inventionthere is provided a method of additive manufacturing of athree-dimensional object. The method comprises sequentially forming aplurality of layers each patterned according to the shape of a crosssection of the object, thereby forming the object. In some embodimentsof the present invention, the formation of at least one of the layerscomprises performing a raster scan to dispense at least a first buildingmaterial composition, and a vector scan to dispense at least a secondbuilding material composition. The vector scan is optionally along apath selected to form at least one structure selected from the groupconsisting of (i) an elongated structure, (ii) a boundary structure atleast partially surrounding an area filled with the first buildingmaterial, and (iii) an inter-layer connecting structure.

According to some embodiments of the invention the first buildingmaterial composition is different from the second building materialcomposition.

According to some embodiments of the invention the first buildingmaterial composition is generally non-electrically conductive, and thesecond building material is generally electrically conductive.

According to some embodiments of the invention at least one of the firstand the second building material compositions comprises a UV curablecomponent.

According to some embodiments of the invention the first and the secondbuilding material compositions are at different temperatures during thedispensing.

According to some embodiments of the invention the structure is embeddedwithin an area formed by the raster scan.

According to some embodiments of the invention the structure is aperipheral with respect to the layer.

According to some embodiments of the invention the path is selected toform a plurality of lines embedded in an area formed by the raster scan.

According to some embodiments of the invention the vector scan is atleast partially simultaneous with the raster scan.

According to some embodiments of the invention the vector scan and theraster scan are performed sequentially.

According to some embodiments of the invention the at least one layer isan inner layer within the plurality of layers.

According to some embodiments of the invention the at least one layer isa topmost or a bottommost layer among the plurality of layers.

According to some embodiments of the invention the at least one layercomprises at least two layers.

According to some embodiments of the invention the method comprisesevaporating solvent from the second building material. According to someembodiments of the invention the solvent comprises water.

According to an aspect of some embodiments of the present inventionthere is provided a circuitry producible by a method described herein.

According to an aspect of some embodiments of the present inventionthere is provided an article of manufacture, comprising a plurality oflayers made of non-electrically conductive UV curable material andfabricated via three-dimensional printing, wherein at least one layer ofthe plurality of layers comprises a pattern of conductive lines made ofelectrically conductive material.

According to some embodiments of the invention the electricallyconductive material is UV curable.

According to an aspect of some embodiments of the present inventionthere is provided a circuitry comprising the article of manufacturedescribed herein.

According to an aspect of some embodiments of the present inventionthere is provided an optoelectronic system comprising the circuitrydescribed herein.

According to an aspect of some embodiments of the present inventionthere is provided a sensor comprising the circuitry described herein.

According to an aspect of some embodiments of the present inventionthere is provided a diode system comprising the circuitry describedherein.

According to an aspect of some embodiments of the present inventionthere is provided a transistor system comprising the circuitry describedherein.

According to an aspect of some embodiments of the present inventionthere is provided a memory system comprising the circuitry describedherein.

According to an aspect of some embodiments of the present inventionthere is provided an imaging system comprising the circuitry describedherein.

According to an aspect of some embodiments of the present inventionthere is provided a display system comprising the circuitry describedherein.

According to an aspect of some embodiments of the present inventionthere is provided a projector display system comprising the circuitrydescribed herein.

According to an aspect of some embodiments of the present inventionthere is provided an identification tag system comprising the circuitrydescribed herein.

According to an aspect of some embodiments of the present inventionthere is provided a smart card system comprising the circuitry describedherein.

According to an aspect of some embodiments of the present inventionthere is provided a battery comprising the circuitry described herein.

According to an aspect of some embodiments of the present inventionthere is provided a system for additive manufacturing of athree-dimensional object. The system comprises a first dispensing headconfigured for performing a raster scan and dispensing a first buildingmaterial composition during the raster scan. The system furthercomprises a second dispensing head configured for performing a vectorscan and dispensing a second building material composition during thevector scan. The system further comprises a controller for controllingthe first dispensing head and the second dispensing head to sequentiallyform a plurality of layers in a configured pattern corresponding to theshape of the object. In some embodiments of the present invention thecontroller is configured to control the second dispensing head todispense the second building material composition along a path selectedto form at least one structure selected from the group consisting of (i)an elongated structure, (ii) a boundary structure at least partiallysurrounding an area filled with the first building material, and (iii)an inter-layer connecting structure.

According to some embodiments of the invention the controller isconfigured to form at least one layer by establishing a raster scan ofthe first head to dispense a non-electrically conductive modelingmaterial and a vector scan of the second head to dispense anelectrically conductive material.

According to some embodiments of the invention at least one of the firstand the second building materials is UV curable, and the system furthercomprises a radiation source.

According to some embodiments of the invention the path is embeddedwithin an area formed by the raster scan.

According to some embodiments of the invention the path is selected toform a plurality of conductive lines embedded within an area formed bythe raster scan.

According to some embodiments of the invention the first and the secondheads are configured to move independently.

According to some embodiments of the invention the first head is rigidlyattached to the second head.

According to some embodiments of the invention the vector scan is atleast partially simultaneous with the raster scan.

According to some embodiments of the invention the vector scan and theraster scan are performed sequentially.

According to some embodiments of the invention the at least one layer isan inner layer within the plurality of layers.

According to some embodiments of the invention the at least one layer isa topmost or a bottommost layer among the plurality of layers.

According to some embodiments of the invention the at least one layercomprises at least two layers.

According to an aspect of some embodiments of the present inventionthere is provided a method of additive manufacturing of athree-dimensional object. The method comprises sequentially forming aplurality of layers each patterned according to the shape of a crosssection of the object, thereby forming the object. In some embodimentsof the present invention the formation of at least one of the layerscomprises dispensing at least a first building material composition at atemperature above 60° C. and at least a second building materialcomposition at a temperature below 40° C.

According to some embodiments of the invention the first buildingmaterial composition is generally non-electrically conductive, and thesecond building material is generally electrically conductive.

According to some embodiments of the invention the dispensing of thefirst building material composition is characterized by raster scan.

According to some embodiments of the invention the dispensing of thesecond building material composition is characterized by raster scan.

According to some embodiments of the invention the dispensing of thesecond building material composition is characterized by vector scan.

According to some embodiments of the invention at least one of the firstbuilding material composition and the second building materialcomposition is UV curable.

Unless otherwise defined, all technical and/or scientific terms usedherein have the same meaning as commonly understood by one of ordinaryskill in the art to which the invention pertains. Although methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of embodiments of the invention, exemplarymethods and/or materials are described below. In case of conflict, thepatent specification, including definitions, will control. In addition,the materials, methods, and examples are illustrative only and are notintended to be necessarily limiting.

Implementation of the method and/or system of embodiments of theinvention can involve performing or completing selected tasks manually,automatically, or a combination thereof. Moreover, according to actualinstrumentation and equipment of embodiments of the method and/or systemof the invention, several selected tasks could be implemented byhardware, by software or by firmware or by a combination thereof usingan operating system.

For example, hardware for performing selected tasks according toembodiments of the invention could be implemented as a chip or acircuit. As software, selected tasks according to embodiments of theinvention could be implemented as a plurality of software instructionsbeing executed by a computer using any suitable operating system. In anexemplary embodiment of the invention, one or more tasks according toexemplary embodiments of method and/or system as described herein areperformed by a data processor, such as a computing platform forexecuting a plurality of instructions. Optionally, the data processorincludes a volatile memory for storing instructions and/or data and/or anon-volatile storage, for example, a magnetic hard-disk and/or removablemedia, for storing instructions and/or data. Optionally, a networkconnection is provided as well. A display and/or a user input devicesuch as a keyboard or mouse are optionally provided as well.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Some embodiments of the invention are herein described, by way ofexample only, with reference to the accompanying drawings. With specificreference now to the drawings in detail, it is stressed that theparticulars shown are by way of example and for purposes of illustrativediscussion of embodiments of the invention. In this regard, thedescription taken with the drawings makes apparent to those skilled inthe art how embodiments of the invention may be practiced.

In the drawings:

FIGS. 1A-1C are schematic illustrations of an additive manufacturingsystem according to some embodiments of the present invention;

FIGS. 2A-2D are schematic illustrations of structures formed in a layerby vector scans according to some embodiments of the present invention;

FIG. 3 which is a schematic illustration of an article of manufacture,according to some embodiments of the present invention; and

FIG. 4 is a schematic illustration of an appliance according to someembodiments of the present invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

The present invention, in some embodiments thereof, relates to AdditiveManufacturing (AM) of an object, more particularly, but not exclusively,to a system and method for additive manufacturing of an object using acombination of materials and/or scanning patterns.

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not necessarily limited in itsapplication to the details of construction and the arrangement of thecomponents and/or methods set forth in the following description and/orillustrated in the drawings and/or the Examples. The invention iscapable of other embodiments or of being practiced or carried out invarious ways.

The method and system of the present embodiments manufacturethree-dimensional objects in a layerwise manner by forming a pluralityof layers in a configured pattern corresponding to the shape of theobjects.

The term “object” as used herein refers to a whole object or a partthereof.

Each layer is formed by AM apparatus which scans a two-dimensionalsurface and patterns it. In some embodiments of the present inventionthe AM apparatus is a three-dimensional printing apparatus.

The scanning of the AM apparatus of the present embodiments can includeraster and/or vector scan.

As used herein “raster scan” refers to a scanning mode in which therelative motion between the dispensing head of the AM apparatus and theworking surface is always parallel to one or two straight lines. In thisscanning mode, the deposition is preferably only during the relativemotion along a straight line.

A representative example of a raster scan is as follows. The dispensinghead moves in a main scanning direction which is parallel to the workingsurface. While scanning, the apparatus visits a plurality of targetlocations on the two-dimensional layer or surface, and decides, for eachtarget location or a group of target locations, whether or not thetarget location or group of target locations is to be occupied bybuilding material, and which type of building material is to bedelivered thereto. The decision is made according to a computer image ofthe surface.

Optionally, once a full scan along the main scanning direction iscompleted, the dispensing head optionally moves in an indexing directionwithout dispensing building material. The indexing direction is alsoparallel to the working surface but is orthogonal to the main scanningdirection. The dispensing head can also perform a reverse scan in themain scanning direction during which it selectively dispenses thebuilding material. The motion in the indexing direction can be at anystage of the scan.

For example, the motion in the indexing direction can be after eachreverse scan is completed or between every two successive forward andreverse scans as known in the art. The dispensing head can includes aplurality of nozzles arranged along the indexing direction, thusreducing the number of scans that are required for completing the layer.

The series of scans performed by the dispensing head during theformation of a single layer in a raster scan is referred to herein as asingle scan cycle. The main scanning direction is referred to herein asthe X direction, and the indexing direction is referred to herein as theY direction. The X and Y directions are typically parallel to theboundaries of the working surface.

As used herein “vector scan” refers to a scanning mode in which therelative motion between the dispensing head of the AM apparatus and theworking surface is along a path which is selected dynamically by acontroller according to the computer image of the layer.

Optionally, the path is curved. Optionally, at least part of the path isnot parallel to the boundaries of the working surface onto which thedispensing occurs.

Thus, unlike raster scan in which any motion of the dispensing head isparallel to the X or Y directions, the motion in vector scan can bealong any path, not necessarily parallel to the X or Y directions.

Typically, the AM apparatus of the present embodiments scans the workingsurface in several passes. This operation is applied when the width ofthe dispensing heads along the Y direction is smaller than the width ofthe working surface and/or when several objects are built on the sameworking surface during a single additive manufacturing batch.

In some embodiments of the present invention the AM apparatus selectsthe scanning mode based on the two-dimensional position datacorresponding to the layer being built. In vector scan, the throughputof a given layer is governed by the area size to be covered bysupporting or building materials, and therefore non-bulky objects arebuilt faster than bulky ones. In raster scan, on the other hand,throughput is not governed necessarily by the area where material needsto be deposited, but it is governed by the number of scanning passesthat the supporting or modeling material dispensing device is requiredto do in order to deposit those materials.

As a matter of example, building a bar with axis parallel to Z axistakes the same time as building a pipe of the same length and diameter,if printed using a raster scanning mode; while building the same bartakes much longer than building the same pipe if a vector scanning modeis used.

Thus in some embodiments, raster scanning is employed when thethroughput obtained is similar or greater than the throughput obtainedalternatively by vector scanning. This depends on system characteristicssuch as scanning speed of raster and vector, raster material depositiondevice width (in Y axis), layer thickness, etc.

In some embodiments, raster deposition is employed for depositing one ormore materials and vector deposition is employed for deposition of oneor more different materials, according to the properties or attributesof the materials being deposited and/or of the properties or attributesdesired to be manifested in the final object, by usage and/or specificlocation of the particular materials selected for deposition.

In some embodiments, both raster scan and vector scan deposit materialsby inkjet.

In some embodiments, the raster scan deposits material by inkjet whilethe vector scan deposits material using an alternative, differenttechnology, for example, extrusion of a melted polymer, pressure baseddispensing system of a liquid or paste like material.

The AM apparatus thus dispenses building material in target locationswhich are to be occupied and leaves other target locations void. Theapparatus typically includes a plurality of dispensing heads, each ofwhich can be configured to dispense a different building material. Thus,different target locations can be occupied by different buildingmaterials. In various exemplary embodiments of the invention theapparatus comprises one or more dispensing heads configured forperforming a raster scan and one or more dispensing heads configured forperforming a vector scan. One or more building materials dispensed byheads configured for performing raster scan may be different from one ormore building materials dispensed by vector heads. Alternatively, one ormore building materials dispensed by raster scanning heads may be thesame as one or more materials dispensed by vector heads.

The types of building materials can be categorized into two majorcategories: modeling material and support material. The support materialserves as a supporting matrix or construction for supporting the objector object parts during the fabrication process and/or other purposes,e.g., providing hollow or porous objects. Support constructions mayadditionally include modeling material elements, e.g. for furthersupport strength.

The modeling material is generally a composition which is formulated foruse in Additive manufacturing and which is able to form athree-dimensional object on its own, i.e., without having to be mixed orcombined with any other substance.

The final three-dimensional object is made of the modeling material ormaterials or a combination of modeling and support materials ormodification thereof (e.g., following curing). All these operations arewell-known to those skilled in the art of solid freeform fabrication.

When the apparatus comprises more than one dispensing heads configuredfor raster scan, at least one of those dispensing heads preferablydispenses modeling material and at least one of those dispensing headspreferably dispenses support material.

In some embodiments of the present invention the apparatus comprisesseveral dispensing heads configured for raster scan, and a singledispensing head configured for vector scan. Alternatively, the apparatuscan comprise several dispensing heads for vector scan.

The raster scan heads and vector scan heads can be physically attachedto each other or they can be configured for independent motion. When theraster scan heads and vector scan heads are physically attached to eachother, the raster and vector scans are executed sequentially orintermittently. When the raster scan heads and vector scan heads areconfigured for independent motion, the raster and vector scans can beexecuted simultaneously, partially simultaneously, intermittently or inan alternating manner.

In some exemplary embodiments of the invention an object is manufacturedby dispensing two or more different modeling materials, each materialfrom a different dispensing head of the AM. The materials andcombination of materials within the layer are selected according to thedesired properties of the object.

A representative and non-limiting example of a system 10 suitable for AMof an object 12 according to some embodiments of the present inventionis illustrated in FIGS. 1A-1C.

System 10 comprises an additive manufacturing apparatus 14 having adispensing unit 21 which comprises a plurality of dispensing heads 21a-d. Optionally, dispensing unit 21 comprises both heads configured forperforming raster scan and heads configured for performing vector scan,e.g. as shown in FIG. 1A. Alternatively, dispensing unit 21 can compriseonly heads configured for performing raster scan. In a different exampleof a system 10, unit 21 comprises a plurality of dispensing heads 21a-c, while a separate head 23 configured for performing vector scandeposition is located externally to unit 21 as illustrated in FIG. 1B.

Each head comprises at least one nozzle through which a buildingmaterial 24 is dispensed. One or more of the heads (e.g., the rasterscan heads) preferably comprises an array of nozzles 22, as illustratedin FIG. 1C.

Preferably, but not obligatorily, apparatus 14 is a three-dimensionalprinting apparatus, in which case the dispensing heads are printingheads, and the building material is dispensed via inkjet technology.This need not necessarily be the case, since, for some applications, itmay not be necessary for the additive manufacturing apparatus to employthree-dimensional printing techniques. Representative examples ofadditive manufacturing apparatus contemplated according to variousexemplary embodiments of the present invention include, withoutlimitation, binder jet—powder-based apparatus, fused deposition modelingapparatus and fused material deposition apparatus.

Each dispensing head is optionally and preferably fed via a buildingmaterial reservoir which may optionally include a temperature controlunit (e.g., a temperature sensor and/or a heating device), and amaterial level sensor. To dispense the building material, a voltagesignal is applied to the dispensing heads to selectively depositdroplets of material via the dispensing head nozzles, for example, as inpiezoelectric inkjet printing technology. The dispensing rate of eachhead depends on the number of nozzles, the type of nozzles and theapplied voltage signal rate (frequency). Such dispensing heads are knownto those skilled in the art of solid freeform fabrication.

Preferably, but not obligatorily, the overall number of dispensingnozzles or nozzle arrays is selected such that about half of thedispensing nozzles are designated to dispense support material and abouthalf of the dispensing nozzles are designated to dispense modelingmaterial.

In some embodiments of the present invention the number of supportdispensing nozzles is about the same as the number of nozzles designatedto dispense a modeling material. When there are two modeling materials,the number of support nozzles is preferably about one third of theoverall number of nozzles.

Yet, it is to be understood that it is not intended to limit the scopeof the present invention and that the number of modeling materialdepositing heads (modeling heads) and the number of support materialdepositing heads (support heads) may differ.

Apparatus 14 can further comprise a curing unit which can comprise oneor more radiation sources 26, which can be, for example, an ultravioletor visible or infrared lamp, or other sources of electromagneticradiation, or electron beam source, depending on the modeling materialbeing used. Radiation source 26 serves for curing or solidifying curablemodeling material.

The dispensing heads and radiation source are preferably mounted in aframe or block 28 which is preferably operative to reciprocally moveover a tray 30, which serves as the working surface. Vector scanprinting heads may be mounted in block 28 or be a separate unit, asshown in FIG. 1B. According to the common conventions, tray 30 ispositioned in the X-Y plane. Tray 30 is preferably configured to movevertically (along the Z direction), typically downward. In variousexemplary embodiments of the invention, apparatus 14 further comprisesone or more leveling devices 32, e.g. a roller 34. Leveling device 32serves to straighten, level and/or establish a thickness of the newlyformed layer prior to the formation of the successive layer thereon.Leveling device 32 preferably comprises a waste collection device 36 forcollecting the excess material generated during leveling. Wastecollection device 36 may comprise any mechanism that delivers thematerial to a waste tank or waste cartridge.

In use, the dispensing heads of system 10 move according to apredetermined scanning mode (raster scan or vector scan), andselectively dispense building material in a predetermined configurationin the course of their passage over tray 30. The building materialtypically comprises one or more types of support material and one ormore types of modeling material. The passage of the dispensing heads ofunit 21 is followed by the curing of modeling material(s) by radiationsource 26. The passage of the dispensing heads can also be followed byleveling device 32 which straightens the layer thus formed.

Once the layer is completed, tray 30 is lowered in the Z direction to apredetermined Z level, according to the desired thickness of the layersubsequently to be printed. The procedure is repeated to formthree-dimensional object 12 in a layerwise manner. Tray 30 canalternatively be displaced in the Z direction before the layer iscompleted, for example, between forward and reverse passages of thedispensing head of unit 21 during a raster scan.

System 10 optionally and preferably comprises a building material supplyapparatus 50 which comprises the building material containers orcartridges and supplies a plurality of building materials to fabricationapparatus 14.

A control unit or controller 52 controls fabrication apparatus 14 andoptionally and preferably also supply apparatus 50. Control unit 52preferably communicates with a data processor 54 which transmits digitaldata pertaining to fabrication instructions based on computer objectdata, e.g., a CAD configuration represented on a computer readablemedium in a form of a Standard Tessellation Language (STL) format or thelike. Typically, control unit 52 controls at least one of the voltageapplied to each dispensing head or nozzle array, the temperature of thebuilding material in the respective dispensing head. Control unit 52also selects the scanning mode of the respective dispensing head.

Once the manufacturing data is loaded to control unit 52 it can operatewithout user intervention. In some embodiments, control unit 52 receivesadditional input from the operator, e.g., using data processor 54 orusing a user interface 16 communicating with unit 52. User interface 16can be of any type known in the art, such as, but not limited to, akeyboard, a touch screen and the like. For example, control unit 52 canreceive, as additional input, one or more building material types and/orattributes, such as, but not limited to, color, characteristicdistortion and/or transition temperature, viscosity, electricalproperty, magnetic property. Other attributes and groups of attributesare also contemplated.

Some embodiments contemplate the fabrication of an object by dispensingdifferent materials from different dispensing heads. These embodimentsprovide, inter alia, the ability to select materials from a given numberof materials and define desired combinations of the selected materialsand their properties or attributes. According to the presentembodiments, the spatial locations of the deposition of each materialwith the layer is defined, either to effect occupation of differentthree-dimensional spatial locations by different materials, or to effectoccupation of substantially the same three-dimensional location oradjacent three-dimensional locations by two or more different materialsso as to allow post deposition spatial combination of the materialswithin the layer, thereby to form a composite material at the respectivelocation or locations.

Any post deposition combination or mix of modeling materials iscontemplated. For example, once a certain material is dispensed it maypreserve its original properties. However, when it is dispensedsimultaneously with another modeling material or other dispensedmaterials which are dispensed at the same or nearby locations, acomposite material having a different property or properties to thedispensed materials is formed.

The present embodiments thus enable the deposition of a broad range ofmaterial combinations, and the fabrication of an object which mayconsist of multiple different combinations of materials, in differentparts of the object, according to the properties desired to characterizeeach part of the object.

Further details on the principles and operations of an AM system capableof dispensing a plurality of modeling materials and modeling materialcombinations is found in U.S. Published Application No. 20100191360, thecontents of which are hereby incorporated by reference.

When the AM is by three-dimensional printing, the viscosity of thebuilding materials is preferably sufficiently low (e.g., 20 cps or less)to allow dispensing by inkjet technology. In AM technique, it isadvantageous to use UV curable materials as the building materials,since such materials enjoy enhanced properties. These types of materialsare typically heated prior to deposition to reduce their viscosity.

Other types of building materials, such as conductive materials or inksand the like, may be used. In some embodiments conductive inks materialsor inks contain a sufficient amount of low viscosity volatile solventsand therefore can be deposited at room temperature or at a temperaturelower than 40° C., or at a sufficiently low temperature at which thereis no significant solvent evaporation at the dispenser/nozzles, prior todispensing.

Electrically conductive inks, for example, are typically produced bydispersing particles of an electrically conductive material, such as,but not limited to, silver or a conductive polymer material (e.g.,PDOT-PSS) in a solvent.

The electrical conductivity increases with the content of conductiveparticles in the solvent. Thus, high conductivity is achieved using ahigh content of conductive particles. Further increment of conductivityis achieved by fusing several conductive particles together. Since theseoperations increase the viscosity of the ink, the conductive inks areprepared with a large amount of volatile solvents to be evaporated insitu.

It was found by the present inventor that it is problematic to exposelow viscosity solvents to high temperatures due to premature solventevaporation while the building material is still in the dispensingheads. It was also found by the present inventors that high temperaturesmay also damage the substrate on which the object is built, for example,when the substrate is a polymer.

The present inventor has therefore realized that it is problematic todispense at the same temperature both UV curable materials which are tooviscous at low temperatures and building materials which includevolatile solvents.

The above problem has been inventively solved by a technique in whichone building material is dispensed at a high temperature (e.g., above60° C. or above 65° C. or above 70° C. or above 75° C. or at least 80°C.) and the other building material is dispensed at a low temperature(e.g., below 40° C. or below 35° C. or below 30° C.).

This can be done by individually controlling the temperature of eachbuilding material while being loaded to the respective dispensing head.Thus, in various exemplary embodiments of the invention controller 52maintains at least two dispensing heads at different temperatures.Optionally and preferably, controller 52 effects raster scans for thedispensing of building materials at higher temperatures, and vectorscans for the dispensing of building materials at lower temperatures.Alternatively, both building materials at higher temperatures andbuilding materials at lower temperatures are dispensed during rasterscans.

In an aspect of some embodiments of the present invention there isprovided a method suitable for additive manufacturing of athree-dimensional object. The method can be executed using an AM system,e.g., system 10. The method comprises sequentially forming a pluralityof layers each patterned according to the shape of a cross section ofthe object. In various exemplary embodiments of the invention at leastone of the layers is formed by performing a raster scan to dispense atleast a first building material composition, and a vector scan todispense at least a second building material composition. The vector andraster scans can, as stated, be sequential or at least partiallysimultaneous.

One or both of the first and second building material compositionsoptionally and preferably comprise UV curing components. In someembodiments, the first building material composition is different fromthe second building material composition. For example, the firstbuilding material composition can be generally non-electricallyconductive, and the second building material can be generallyelectrically conductive.

As used herein “generally non-electrically conductive” refers to aconductivity at room temperature of less than 1 S/m or less than 0.1 S/mor less than 0.01 S/m or less than 10⁻³ S/m or less than 10⁻⁴ S/m orless than 10⁻⁵ S/m.

As used herein “generally electrically conductive” refers to aconductivity at room temperature of at least 1 S/m or at least 10 S/m orat least 100 S/m or at least 1000 S/m or at least 10,000 S/m or at least100,000 S/m.

The first and second building material compositions can be dispensed atthe same or different temperatures, as desired. For example, the secondbuilding material composition can be a UV curable material includingvolatile solvent (e.g., water) and the first building materialcomposition can be a UV curable material which is devoid of or has areduced amount of volatile solvent. In these embodiments, the secondbuilding material composition can be dispensed at a temperature which islower (e.g., by at least 20° C.) than the dispensing temperature of thefirst building material composition. Following the dispensing, thesolvent can be evaporated from the second building material.

Vector scanning is advantageous for printing conductive “tracks”, suchas continuous elongated structures, as the vector deposition head maycontinuously deposit conductive material in its movement parallel to theXY plane. The vector dispensing heads may be located separately andproximate to the raster dispensing heads, and move over the fabricationarea separately or in concert with the raster heads, and dispensingmaterial separately and substantially simultaneously or sequentially tothe raster dispensing, depending on the existence and spatial locationof conductive tracks within a layer. For example, the raster dispensingheads may scan and selectively dispense building material, e.g. anon-conductive material, to form a layer, followed by selective vectordispensing of another material in predetermined spatial locations withinthe layer, e.g. a conductive material to form a conductive track orpattern with the layer.

The vector scan is along a path selected to form at least one structurein the layer. The structure can be for example, an elongated structure.

The term “elongated structure” refers to a three-dimensional body inwhich one of its dimensions is at least 2 times, more preferably atleast 10 times, more preferably at least 100 times, e.g., at least 500times larger than any of the other two dimensions. The largest dimensionof the elongated solid structure is referred to herein as thelongitudinal dimension, and the dimensions are referred to herein as thetransverse dimensions.

A representative example of a plurality of elongated structures 62formed in a layer 60 by vector scans are illustrated in FIG. 2A.

The structure can also be a boundary structure at least partiallysurrounding an area filled with the first building material. Arepresentative example of a boundary structure 66 formed in layer 60 bya vector scans is illustrated in FIG. 2B.

The structure can also be an inter-layer connecting structure. In theseembodiments, the structure is preferably small (e.g., less than 1%)relative to the overall size of the layer. A representative example ofinter-layer structure 68 connecting two layers 60 and 70 is illustratedin FIG. 2C.

The structure can also be embedded within an area formed by the rasterscan. For example, referring again to FIG. 2A, the major area 72 oflayer 60 can be formed by raster scan wherein structures 62 can beembedded within area 72.

The structure can also be peripheral with respect to a layer. Thisembodiment is illustrated in FIG. 2D showing layer 60 and structure 74at its periphery.

The combination of raster and vector scans can be in any of the layersforming the object. Specifically, in some embodiments the combination ofraster and vector scans is performed for an inner layer within aplurality of layers, in some embodiments the combination of raster andvector scans is performed for a topmost layer, and in some embodimentsthe combination of raster and vector scans is performed for a bottommostlayer. The combination of raster and vector scans can also be performedin a plurality of layers, as desired.

Reference is now made to FIG. 3 which is a schematic illustration of anarticle of manufacture 80, according to some embodiments of the presentinvention.

Article of manufacture 80, typically comprises a plurality of layers 60(only one layer shown in the top view of FIG. 3) made ofnon-electrically conductive material and fabricated viathree-dimensional printing, wherein at least one of the layers comprisesa pattern 82 of conductive lines made of electrically conductivematerial. Pattern 82 can be deposited on or embedded in regions 84 ofnon-electrically conductive material. Article of manufacture 80 can befabricated by system 10 and/or by method described above.

In some embodiments of the present invention article of manufacture 80is a circuitry, e.g., a circuit board. FIG. 4 is a schematicillustration of an appliance 90 which includes circuitry 80. Appliance90 is typically, but not necessarily, a large area electronic appliance.Representative examples of appliances suitable for the presentembodiments include, without limitation, an optoelectronic system, adisplay system (e.g., an active matrix display system), a projectordisplay system, a sensor, an identification tag, a memory medium, asmart card (e.g., a microprocessor card, cryptographic card, ATM card,subscriber identity module card also known as SIM card), and a projectordisplay, a battery. Appliance 90 can also be an electronic componentsuch as a diode system and a transistor system.

In some embodiments, materials able to solidify after deposition areemployed and deposited from certain dispensers, for example UV curablematerials. In addition materials which do not solidify are used anddispensed from other dispensers, for example electrolytes. In addition,materials which after deposition result in an electrically conductivematerial are used as well. All may be used together to build a singledevice such as, for example, a battery.

It is expected that during the life of a patent maturing from thisapplication many relevant electronic appliances, particularly in thefield of large area electronics will be developed and the scope of theterm “appliance” is intended to include all such new technologies apriori.

One or more operations of the method of the present embodiments areimplemented by a computer. Computer programs implementing the method ofthe present embodiments can commonly be distributed to users on adistribution medium such as, but not limited to, a floppy disk, aCD-ROM, a flash memory device and a portable hard drive. From thedistribution medium, the computer programs can be copied to a hard diskor a similar intermediate storage medium. The computer programs can berun by loading the computer instructions either from their distributionmedium or their intermediate storage medium into the execution memory ofthe computer, configuring the computer to act in accordance with themethod of this invention. All these operations are well-known to thoseskilled in the art of computer systems.

The computer implemented method of the present embodiments can beembodied in many forms. For example, it can be embodied in on a tangiblemedium such as a computer for performing the method operations. It canbe embodied on a computer readable medium, comprising computer readableinstructions for carrying out the method operations. It can also beembodied in electronic device having digital computer capabilitiesarranged to run the computer program on the tangible medium or executethe instruction on a computer readable medium.

It is expected that during the life of a patent maturing from thisapplication many relevant modeling materials for AM will be developedand the scope of the term modeling material is intended to include allsuch new technologies a priori.

As used herein the term “about” refers to ±10%.

The word “exemplary” is used herein to mean “serving as an example,instance or illustration.” Any embodiment described as “exemplary” isnot necessarily to be construed as preferred or advantageous over otherembodiments and/or to exclude the incorporation of features from otherembodiments.

The word “optionally” is used herein to mean “is provided in someembodiments and not provided in other embodiments.” Any particularembodiment of the invention may include a plurality of “optional”features unless such features conflict.

The terms “comprises”, “comprising”, “includes”, “including”, “having”and their conjugates mean “including but not limited to”.

The term “consisting of” means “including and limited to”.

The term “consisting essentially of” means that the composition, methodor structure may include additional ingredients, steps and/or parts, butonly if the additional ingredients, steps and/or parts do not materiallyalter the basic and novel characteristics of the claimed composition,method or structure.

As used herein, the singular form “a”, “an” and “the” include pluralreferences unless the context clearly dictates otherwise. For example,the term “a compound” or “at least one compound” may include a pluralityof compounds, including mixtures thereof.

Throughout this application, various embodiments of this invention maybe presented in a range format. It should be understood that thedescription in range format is merely for convenience and brevity andshould not be construed as an inflexible limitation on the scope of theinvention. Accordingly, the description of a range should be consideredto have specifically disclosed all the possible subranges as well asindividual numerical values within that range. For example, descriptionof a range such as from 1 to 6 should be considered to have specificallydisclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numberswithin that range, for example, 1, 2, 3, 4, 5, and 6. This appliesregardless of the breadth of the range.

Whenever a numerical range is indicated herein, it is meant to includeany cited numeral (fractional or integral) within the indicated range.The phrases “ranging/ranges between” a first indicate number and asecond indicate number and “ranging/ranges from” a first indicate number“to” a second indicate number are used herein interchangeably and aremeant to include the first and second indicated numbers and all thefractional and integral numerals therebetween.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable sub-combination or as suitable in any other describedembodiment of the invention. Certain features described in the contextof various embodiments are not to be considered essential features ofthose embodiments, unless the embodiment is inoperative without thoseelements.

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims.

All publications, patents and patent applications mentioned in thisspecification are herein incorporated in their entirety by referenceinto the specification, to the same extent as if each individualpublication, patent or patent application was specifically andindividually indicated to be incorporated herein by reference. Inaddition, citation or identification of any reference in thisapplication shall not be construed as an admission that such referenceis available as prior art to the present invention. To the extent thatsection headings are used, they should not be construed as necessarilylimiting.

What is claimed is:
 1. A system for additive manufacturing of athree-dimensional object, comprising: a first dispensing head configuredfor dispensing a first building material composition; a seconddispensing head configured for performing a vector scan and dispensing asecond building material composition by a technology other than aninkjet technology during said vector scan; and a controller forcontrolling said first dispensing head and said second dispensing headto sequentially form a plurality of layers in a configured patterncorresponding to the shape of the object, and to maintain said firstbuilding material composition in said first dispensing head at atemperature above 60° C., and said second building material compositionin said second dispensing head at a temperature below 40° C.
 2. Thesystem of claim 1, wherein said first building material composition isgenerally non-electrically conductive, and said second building materialis generally electrically conductive.
 3. The system of claim 1, whereinsaid dispensing said first building material composition ischaracterized by raster scan.
 4. The system of claim 3, wherein saidfirst dispensing head comprises an inkjet dispensing head.
 5. The systemof claim 1, wherein at least one of said first building materialcomposition and said second building material composition is UV curable.6. The system of claim 1, wherein said second building material containsa volatile solvent.